Premium
Improvement of Creep Resistance of Sintered Silicon Nitride by Hot Isostatic Exudation of Intergranular Glass
Author(s) -
Rouxel Tanguy,
Besson JeanLouis,
Goursat Paul
Publication year - 1993
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1993.tb04017.x
Subject(s) - materials science , intergranular corrosion , hot isostatic pressing , creep , borosilicate glass , metallurgy , silicon nitride , amorphous solid , composite material , phase (matter) , hot pressing , nitride , silicon , sintering , microstructure , layer (electronics) , chemistry , organic chemistry
Postsintering treatment of pressureless‐sintered silicon nitride at 1250°C (i.e., above the glass transition temperature of the amorphous phase) by hot isostatic pressing was performed to diminish the quantity of residual intergranular amorphous phase that results from densification aids. The samples were first embedded in a powder (SiC or Al 2 O 3 ), which worked as a diffusion barrier and a pressure transmitter; then, both sample and surrounding powder were encapsulated in evacuated tubes of borosilicate glass or stainless steel. Energy dispersive X‐ray spectrometry proved that, during the treatment, a noticeable amount of intergranular vitreous phase exuded out of the sample into powder pores. As a consequence, the creep resistance was enhanced by a factor of 3. When the HIP treatment was associated with a subsequent crystallization treatment, a further improvement in creep resistance was obtained.